Here is a question from Eric:
I started composting roughly a year ago and now winter has come. I was
using a 21gallon drum when I started and asked for my birthday in July
for a composting bin(my girlfriend and parents thought I was crazy but
accepted it). I just turned 17 and I feel the need to do my part in
helping the planet…granted I want to change the way we live today
and I hope to do so in the future but as I am 17 this is the most I
can do right now. I have 2 Earth Machine Composting Bins. The picture
would be on google images if you don’t know this bin. I noticed your
website about winter composting and your methods and I am just
wondering how YOU would insulate the bin if you owned it.
I also have two Earth Machines in my backyard! They are the most common backyard composter in my neck of the woods since the regional waste department gives them away for free! I generally don’t attempt to protect mine over the winter, simply because my trench bed systems are better suited for the job – but it certainly can be done.
However, it’s important to point out right off the bat, that the activity inside the system will be largely dependent on how severe your winters are. If you live in North Dakota, Northern Minnesota, Alaska etc, you may be able to provide enough protection to keep the worms (or at least some cocoons) alive, but you almost certainly won’t be able to actually keep the system totally active (without artificial intervention, that is). If I were doing this in my area (zone ~5a), I would likely be aiming for worm survival, not active composting. My actual winter systems are always substantially larger.
If you DO live in a warmer zone than me though, you should be able to keep the system at least semi-active during the winter months. Just keep adding waste materials to it and see how it goes! If you end up filling it all the way to the top, this is probably an indication that the composting process has slowed down considerably. I recommend buying yourself a long stemmed compost thermometer, since this will help you to determine how things are coming along down in the bin as well.
Anyway, here are some of the things I would recommend…
Hopefully your two bins are side-by-side – this will help you to create more of a “united front” against the cold. Plus, it will save you time as far as setting everything up goes. Assuming this is going to be a one-off, protect-it-then-let-it-sit affair, you will likely want to time your operation strategically. No use getting everything going before the “real” cold hits (really hard frosts – maybe even a little snow) because you might end up overheating the bin(s) and burning through your “fuel”.
The first thing I would recommend for any type of backyard composter bin (assuming it is open-bottomed – which, by the way, is fairly important for a winter bin) is to dig a decent pit down below it, assuming you don’t have one already – this might be 1-2 ft in depth. Of course, the diameter of the hole should be smaller than the diameter of the bin so that it sits nicely over top. In the bottom of this hole I would add a bunch of bedding material and “food”. Because you are looking for more of a “time release” food value, you definitely don’t need to age (or finely chop etc) the wastes before you add them – unless of course we’re talking about yard wastes like old weeds etc (which should be chopped up a bit). If you can get some nice aged manure, this would be a great addition as well. Over top of your pit zone, I would simply add the material that was already in the composter.
If you live in a region with lots of fall leaves, I highly recommend you use these for insulation (also great to add to the bin). Straw and hay can also work really well. All you need to do is heap them up around the outside of your bins. Ideally – assuming you have enough leaves etc – I would pile them all the way to the top of the bins, and then would even take things a step further by securing a tarp over top. If you live in a region that receives lots of snow, heaping a lot of it over top of the tarp can serve as a great extra layer of insulation as well.
By the way – I realized while writing my response that you didn’t actually mention worms at all, so perhaps you are not planning to vermicompost. The good news is that the same basic principles apply – the key is to provide enough “fuel” (waste materials) and insulation to at least keep the system from freezing, if not totally active. Microbial activity will add warmth, and your insulation system will help to keep it in.
Hope this helps, Eric!